KR19980018300A - Voltage Controlled Oscillator and its Adjustment Method - Google Patents

Abstract

A voltage-controlled oscillator according to the present invention includes a resonator for generating an oscillation signal including a frequency responsive to a control voltage, amplifying means for amplifying an oscillation signal,

Oscillation frequency adjustment means for adjusting the frequency of the oscillation signal and voltage control sensitivity adjustment means for adjusting the voltage control sensitivity of the oscillation signal. The present invention also provides a method of adjusting a three-stage voltage-controlled oscillator.

Description

Voltage Controlled Oscillator and Method of Adjusting It.

Figure 1a illustrates a voltage controlled oscillator according to an embodiment of the present invention.

Figure 1b is a frequency and voltage characteristic diagram showing the adjustment process.

Fig. 2 is an exploded perspective view showing a laminated structure in the embodiment of Fig. 1; Fig.

Figure 3a-3e show the lamination process according to one embodiment of Figure 1;

Figure 4a is a sectional view taken along the line E-E of Figure 3e.

Figure 4b is a cross-sectional view taken along line F-F of Figure 7e.

5A is a circuit diagram showing another example of the voltage-controlled oscillator of the present invention. Fig.

Figure 5b shows the frequency and voltage characteristic diagrams showing the adjustment process.

FIG. 6 is an exploded perspective view showing a laminated structure in the embodiment of FIG. 5; FIG.

7A to 7E are diagrams showing the lamination step in the embodiment of FIG. 5;

8A is a circuit diagram showing another example of the voltage-controlled oscillator of the present invention.

Figure 8b and Figure 8b are frequency and voltage characteristic diagrams illustrating the adjustment process.

9A and 9B are circuit diagrams showing another example of the voltage-controlled oscillator of the present invention.

Figure 9b is a frequency and voltage characteristic diagram in which the adjustment process is shown.

10 is a circuit diagram showing a conventional voltage-controlled oscillator.

10B is a frequency and voltage characteristic diagram for explaining a problem of a conventional voltage-controlled oscillator.

The present invention relates to a high-frequency voltage-controlled oscillator having an electronic component mounted on a substrate made of a resonator and a laminate body made of a laminate structure, and a method of adjusting the voltage-controlled oscillator, and more particularly to a radio- And a method of adjusting the voltage controlled oscillator.

As shown in the circuit diagram of FIG. 10A, the conventional voltage-controlled oscillator includes an inductor L1 chokeing a high-frequency component, a capacitor C1 intercepting a high-frequency component, a capacitor C2 intercepting a DC component, a variable capacitive diode D, a resonator L2, A coupling capacitor C 4, an amplifying transistor T, a feedback capacitor C 5, and resistors R 1 and R 2 forming a peripheral circuit of the transistor T.

In the voltage-controlled oscillator, the capacitance Cv of the variable capacitive diode D changes in accordance with the voltage supplied to the input terminal 1. The resonance frequency f (V _T ) of the voltage-controlled oscillator is expressed by the following equations (1) and (3), where the inductance of the resonator L2 is L ₂ , the capacitance of the capacitor C ₂ is C ₂ and the capacitance of the capacitor C ₃ is C ₃ to be.

_{f (V T) = 1 /} [2π {1 / (1 / C 2 + 1 / Cv) + C 3} L 2] 1/2 ... (One)

Cv = C ₀ + aV _T ... (2) (a 0)

dF / dV _T = dF (V _T , C ₂ , C ₃ , C ₀ , a) dV _T

= -1 [1 / {32? ⁴ f (V _T ) ³ }] {aL ₂ / (1 + Cv / C ₂ ) ² } (3)

The capacitor C2, which is disposed between the input terminal 1 and the transistor T, is mounted on the substrate of the laminate body as a chip, or buried in the substrate of the laminate body. A conductor is formed on the surface of the laminated body accompanied by the resonator L2 as described in Japanese Unexamined Patent Publication No. 1992-329705 and the conductor is trimmed to adjust the capacitance of the capacitor C3, When the frequency f (V _M ), that is, the center voltage V _M, is given from the input terminal, the oscillation frequency is adjusted.

However, in the voltage controlled oscillator, not only the oscillation frequency f (V _T ) but also the voltage control sensitivity df / dV _T (V _T ) have upper and lower limits. That is, as shown in the graph of FIG. 10b, it is necessary to satisfy the following expressions (4) - (6).

f _L2 ( _VL ) f _L1 ... (4)

f _H1 f ( _VH ) f _H2 ... (5)

_{(f H1 - f L1) /} (V H - V L) df / dV T (V T)

_{(f H2 - f L2) /} (V H - V L) ... (6)

Where V _M is the center voltage, V _H is the upper limit voltage applied to the input terminal 1, V _L is the lower limit voltage, f (V _L ) is the oscillation frequency at the lower limit voltage V _L , f (V _H ) the oscillation frequency of the V _H, f _L1 is a lower limit voltage of the upper limit frequency of oscillation, f _L2 of the V _L is a lower limit oscillating frequency at the lower limit voltage V _L, f _H1 is the upper limit voltage lower limit of the oscillation frequency, f _H2 in V _H is an upper limit And the upper limit oscillation frequency at the voltage V _H , respectively.

When trimming is performed only for the center frequency f (V _M ) according to the conventional method, as shown in FIG. 10, the voltage control sensitivity df / dV _T is deflected from the straight line S1 at which the reference line starts to the straight lines S2 and S3. Therefore, the voltage control sensitivity df / dV _T is biased from the upper and lower limits expressed by equation (6). The main causes of the deviation of the voltage control sensitivity df / dV _T from the upper and lower limits are described below. That is, as can be seen from the equations (1) and (3), the oscillation frequency f (V _T ) depends on the voltage variable capacitance Cv of the variable capacitance diode D, _{As 0} and a value fluctuate greatly, they fluctuate widely. For this reason, productivity in the manufacturing process deteriorates.

The present invention provides a voltage controlled oscillator capable of adjusting the voltage control sensitivity by solving the above problems and a method of adjusting the voltage controlled oscillator. As a result, it is possible to greatly improve the productivity in the manufacturing process.

In order to achieve the above object, a voltage-controlled oscillator according to the present invention is disposed between an input terminal (1) to which a control voltage is supplied and an amplifying transistor (T), and a main inductor A capacitor C2 for voltage control sensitivity adjustment connected on a line disposed between the electrodes L2 and L2; And a capacitor C3 for oscillation frequency adjustment in parallel with the main inductor L2 forming a resonator.

The voltage-controlled oscillator according to the present invention further includes an oscillation frequency adjusting inductor L3 disposed between the line 2 connecting the input terminal 1 to which the control voltage is supplied and the amplifying transistor T and the main inductor L2 forming the resonator; And a voltage control sensitivity adjusting inductor L4 connected on the line 2 arranged between the heating terminal of the variable capacitance diode D and the heating terminal of the oscillation frequency adjusting inductor L3.

The voltage controlled oscillator according to the present invention further includes an oscillation frequency adjusting inductor L3 connected between the line 2 connecting the input terminal 1 to which the voltage is supplied and the amplifying transistor T and the main inductor L2 forming the resonator; And a voltage control sensitivity adjusting capacitor C2 disposed on the line 2 between the heating terminal of the variable capacitance diode D and the heating terminal of the oscillation frequency adjusting inductor L3.

The voltage controlled oscillator according to the present invention may further include an oscillation frequency adjustment capacitor C3 in parallel with the main inductor L2 forming the resonator. (2) for connecting the input terminal (1) for supplying the control voltage and the amplifying transistor (T), and a voltage (V) arranged between the heating terminal of the variable capacitive diode (D) and the heating terminal of the resonator forming main inductor And a control sensitivity adjusting inductor L4.

In the voltage controlled oscillator according to the present invention, a capacitor constituting the oscillator frequency adjusting capacitor C3 and / or the inductor L3 is formed on the surface of the substrate of the voltage controlled oscillator, and a voltage control sensitivity adjusting capacitor C2 And / or a conductor constituting the inductor L4 are formed.

Further, a method of adjusting a voltage-controlled oscillator according to the present invention may include a step of performing functional trimming on a capacitor constituting a capacitor C3 and / or an inductor L3 which adjusts an oscillation frequency, and then roughly adjusting an oscillation frequency; Performing functional trimming on the capacitor constituting the capacitor C2 and / or the inductor L4 for adjusting the voltage control sensitivity and adjusting the voltage control sensitivity to a specific value; And performing a functional trimming again on the conductor constituting the capacitor C3 and / or the inductor L3 that adjusts the oscillation frequency to adjust the oscillation frequency to a specific value. In this case, the functional trimming is defined as the trimming performed while the characteristics of the voltage-controlled oscillator are measured.

According to the present invention, the oscillation frequency is adjusted when functional trimming is performed on an inductor connected in series to the resonator or a capacitor connected in parallel to the resonator. According to the present invention, functional trimming is performed when the voltage control sensitivity adjusting capacitor or the inductor is aligned on the line. Accordingly, since the voltage control sensitivity is adjusted, not only the oscillation frequency but also the voltage control sensitivity can be adjusted according to the present invention.

Next, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The voltage controlled oscillator according to the first embodiment of the present invention will be described with reference to FIGS. Fig. 1 (a) shows an example of a circuit in a voltage-controlled oscillator, and this circuit diagram differs from the conventional circuit diagram shown in Fig. 10 (a) in the following points. Capacitor C2, which is connected to lead 2 and which is located between the heating terminal of variable capacitance diode D and the heating terminal of resonator L2, is used to block DC current as well as to adjust voltage control sensitivity.

Fig. 2 is a view showing the structure of each layer of the voltage-controlled oscillator, Fig. 3 is a diagram showing the positional relationship of the conductor pattern on each layer and the manufacturing process. 4A is a cross-sectional view showing an adjustment portion of this embodiment. 3A and 3E are dielectric layers made of alumina or the like. Reference numerals 4a and 4b denote ground conductors formed on the dielectric layers 3a and 3c, L2 denote ground conductors formed on the ground conductors 4a, And a strip line resonator connected to the first and second electrodes 4a and 4b.

L1 is an inductor L1 that chokes high-frequency current as a conductor formed on the dielectric layers 4a, 4b. Reference numerals 5a and 5b denote conductors made of a capacitor C2. Reference numeral 6 denotes a conductor opposed to the ground conductor 4b, and the conductor 6 and the ground conductor 4b constitute a capacitor C3 for adjusting the oscillation frequency. The conductors 4a, 4b, 5a, 5b, 6 are made of silver, silver alloy, or the like.

On the uppermost dielectric layer 3e, a transistor T, capacitors C1 and C4, a variable capacitive diode D, and the like are disposed as shown in FIG.

The voltage-controlled oscillator is manufactured as follows.

- Conductors are formed on the dielectric layers 3a and 3e made of a dielectric sheet as shown in Figs. 3a to 3e,

The conductor pattern shown in FIG. 1A is formed on the dielectric sheet.

- These dielectric sheets are overlapped with each other to perform thermocompression bonding.

- The laminate body is cut according to the dimensions of each voltage-controlled oscillator.

- Apply heat to the laminate body.

- The lateral terminal electrodes (not shown) are formed by printing or plating,

Capacitors C1 and C4, resistors R1 and R2, variable capacitive diodes D, transistors T and other electrical components not shown in the figure are attached to the upper surface of the laminate body by soldering.

As shown in FIG. 2, FIG. 3 and FIG. 4a, when the voltage-controlled oscillator is manufactured by the above process, one end of the main inductor L2 constituting the oscillator is connected to the upper ground conductor 4a and the upper ground conductor 4a via the through- And the other end of the main inductor L2 is connected to the conductor 5b for the capacitor which is mounted on the fifth dielectric layer 3e via the through hole 8. The capacitor conductor 5b is connected to the lower ground conductor 4b.

1B is a diagram showing the relationship between the voltage V _T and the oscillation frequency f in order to explain a method of adjusting the voltage-controlled oscillator of this embodiment. The straight lines a1 - a4 in FIG. 1 (b) show the (fV) characteristic. That is, the straight lines a1 to a4 in FIG. 1 (b) show frequency and voltage characteristics in each adjustment step. The frequency f (V _M ) at the center voltage V _M is set to be lower than the target frequency f ₀ before the adjustment step of the voltage controlled oscillator as indicated by a straight line a1, and the slope of the specific curve (fV) As shown in FIG. First, as shown in FIG. 3E, the frequency f (V _M) at the center voltage V _M by the trimming 10 of the conductor 6 of the capacitor C3 that adjusts the oscillation frequency is shown on the straight line a2 of FIG. 1 Is adjusted to be lower than the Mokpo frequency f ₀ as shown in FIG.

Next, as shown in FIG. 3E, the voltage control sensitivity df / dV _T is adjusted to the target sensitivity as indicated by the straight line a3 in FIG. 1B by trimming (11) of the capacitor C2 which adjusts the voltage control sensitivity.

Next, as shown in FIG. 3E, the center frequency f (V _M ) is adjusted to the target frequency f ₀ by the trimming 12 of the capacitor C 3 for adjusting the oscillation frequency as indicated by the straight line a 4 of FIG. do.

When the voltage control sensitivity and the oscillation frequency are controlled as described above, the productivity of the manufacturing process can be improved while preventing the voltage control sensitivity from being weakened. If trimming is performed in three steps, high-precision adjustment becomes possible.

A second embodiment of the present invention will be described with reference to FIG. 4b and FIGS. 5 to 7. FIG. 5A, the inductor L3 for adjusting the oscillation frequency is connected between the main inductor L2 forming the resonator and the line 2. The line 2 is connected to the input terminal 1 to which the control voltage is supplied And is disposed between the amplification transistors T. On the line 2, the inductor L4 for adjusting the voltage control sensitivity is connected between the heating terminal of the variable capacitive diode D and the heating terminal of the inductor L3 for adjusting the oscillation frequency.

FIG. 6 is a perspective view showing the structure of each layer for realizing this example, and FIG. 7 is a diagram showing the positional relationship of conductor patterns on each layer in the manufacturing process. 4b is a cross-sectional view showing an adjustment part of this example. In FIGS. 2, 3, 6 and 7, the same elements are denoted by the same reference numerals. 7a to 7e show the sequence of the laminating process. 6 and 7, reference symbol L3 denotes a conductor constituting the inductor L3 for adjusting the oscillation frequency. When trimming is performed as indicated by reference numeral 13-15, the length of the passage through which the current flows is increased, and the inductance is increased to lower the oscillation frequency.

6 and 7, L4 is a conductor constituting the inductor L4 for adjusting the voltage control sensitivity. The voltage control sensitivity can be increased when the trimming is performed by the reference numeral 16.

As shown by line b1 in FIG. 5b, before the adjustment is made, in the case of this embodiment, the voltage-controlled oscillator is set as follows. The frequency f (V _M ) at the center voltage is set to be higher than the target frequency f ₀ , and the slope of the specific curve of the voltage control sensitivity (fV) is set to be smaller than the slope of the target characteristic curve of (fV). First, by the trimming of the inductor L3 connected in series with the inductor L2 which is a resonator, the length of the passage through which the current flows by the trimming indicated by reference numeral 13-15 in Fig. 7e becomes large so that the inductance can be increased. The center oscillation frequency f (V _M ) becomes close to the target frequency f ₀ as shown by the straight line b ₂ in FIG. 5 (b).

Next, the inductor L4 is trimmed, that is, the inductance is increased by the trimming shown in Fig. 7E. So that the voltage control sensitivity is adjusted as indicated by a straight line in FIG. 5b. At this time, the oscillation frequency is lowered at the same time.

Next, when additional trimming is performed on the inductor L3 connected in series to the resonator main inductor L2, the center frequency f (V _M ) is adjusted to the target oscillation frequency f ₀ as shown in FIG. 5B.

When the adjustment is performed in three stages as described above, the same effects as those of the first embodiment described above can be obtained.

Figure 8a shows a third embodiment of the present invention. The third embodiment is configured as follows. A voltage control sensitivity adjusting capacitor C2 shown in the first to fourth diagrams is used instead of the inductor L4 for adjusting the voltage control sensitivity in the second embodiment shown in FIGS.

In the embodiment of FIG. 8A, the setting is performed as follows. The frequency f (V _M ) of the center voltage is higher than the target frequency f ₀ and the slope of the characteristic curve of the voltage control sensitivity is (fV) as shown by the line C 1 in FIG. 8 Is larger than the slope of the target characteristic curve. First, by the trimming of the inductor L3 connected in series to the inductor L2 constituting the resonator, the length of the passage through which the current flows increases by the trimming indicated by reference numeral 13-15 in Fig. 7e, and the inductance increases. As a result, the center oscillation frequency f (V _M ) approaches the target frequency f ₀ as shown by the straight line c 2 in FIG. 8b.

Next, trimming is performed on the voltage control sensitivity adjusting capacitor C2, and the capacitance is decreased. Thereby, the voltage control sensitivity is adjusted (lowered) as indicated by the straight line 3 in FIG. 8b. At this time, the oscillation frequency increases at the same time.

Next, the to the inductor L3 connected in series to the resonator L2, as indicated by the straight line c4 8b degrees also subjected to trimming to adjust the center oscillating frequency f (V _M) to the target frequency f _0. The effects described above can be obtained through such an example.

9A shows a fourth embodiment of the present invention, and is constructed as follows. That is, in the embodiment shown in Fig. 4a, the voltage control sensitivity adjusting inductor L4 shown in Figs. 4b to 7 is arranged instead of the capacitor C2 for adjusting the voltage control sensitivity.

In the embodiment shown in FIG. 9A, the setting is performed as follows. That is, the frequency f (V _M ) at the center voltage is lower than the target frequency f ₀ and the slope of the characteristic curve of the voltage control sensitivity (fV) is (fV ) Is smaller than the slope of the target characteristic curve. First, the capacitor C3 that adjusts the oscillation frequency connected in parallel to the inductor L2 constituting the resonator is trimmed to set the center oscillation frequency f (V _M ) to be slightly higher than the target frequency f ₀ as shown by the straight line d2 in FIG. 9b .

Next, the inductance is increased by trimming the inductor L4 that adjusts the voltage control sensitivity. As a result, the voltage control sensitivity is adjusted to the target sensitivity (high) as indicated by the straight line d3 in FIG. 9b. At this time, the oscillation frequency is simultaneously lowered.

Next, as shown by the straight line d4 in FIG. 9b, when trimming is performed on the capacitor C3 in parallel with the resonator L2, the central oscillation frequency f (V _M ) is adjusted to the target frequency f ₀ . The effects described above can be obtained through such an example.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. That is, the modification of the material of the component, the modification of the arrangement of the electronic components to be mounted, the adoption of the additional lamination structure in place of the electronic component, and the like will be described. As well as capacitors and inductors for oscillation frequency adjustment, as well as capacitors and inductors for voltage control sensitivity adjustment, both of them can be used.

According to the present invention, not only capacitors and inductors for oscillation frequency adjustment but also capacitors or inductors for voltage control sensitivity adjustment are provided. Therefore, the voltage control sensitivity can be adjusted and the productivity in the manufacturing process can be improved.

Further, according to the present invention, trimming can be easily performed since the adjusting capacitor and / or the inductor are disposed on the substrate surface.

Further, according to the present invention, since adjustment is performed in three steps, adjustment with high accuracy can be performed.

Claims (15)

A resonator for generating an oscillation signal including a frequency responsive to the control voltage; Amplification means for amplifying the oscillation signal, Oscillation frequency adjusting means for adjusting the frequency of the oscillation signal, And voltage control sensitivity adjusting means for adjusting voltage control sensitivity of the oscillation signal. The method according to claim 1, The resonator includes an input terminal to which a control signal is applied, a variable capacitive diode, and a main inductor, Wherein the oscillation frequency adjusting means includes a first variable capacitor connected in parallel with the main inductor of the resonator, The voltage control sensitivity adjusting means includes a first variable capacitor disposed between an input terminal and the amplifying means and disposed between a heating terminal of the variable capacitance diode and a heating terminal of the main inductor of the resonator Voltage controlled oscillator. The method according to claim 1, Wherein the resonator includes an input terminal to which a control signal is applied, a variable capacitive diode and a main inductor, Wherein the oscillation frequency adjusting means includes a first variable inductor disposed between the input terminal and the amplifying means and connected in series with the main inductor of the resonator, Wherein the voltage control sensitivity adjusting means includes a first variable inductor disposed between a heating terminal of the variable capacitance diode and a heating terminal of the first variable inductor. The method according to claim 1, The resonator includes an input terminal to which a control signal is applied, a variable capacitive diode, and a main inductor, The oscillation frequency adjusting means includes a variable inductor connected in series with the main inductor of the phonon resonator disposed between the input terminal and the amplifying means, Wherein the voltage control sensitivity adjusting means includes a variable capacitor disposed between a heating terminal of the variable capacitance diode and a heating terminal of the variable inductor. The method according to claim 1, The resonator includes an input terminal to which a control signal is applied, a variable capacitive diode, and a main inductor, Wherein the oscillation frequency adjusting means includes a variable capacitor connected in parallel with the main inductor of the resonator, Wherein the voltage control sensitivity adjusting means includes a variable inductor disposed between the input terminal and the amplifying means and disposed between a heating terminal of the variable capacitance diode and a heating terminal of the main inductor of the resonator, oscillator. The method according to claim 1, Wherein the oscillation frequency adjusting means and the voltage control sensitivity adjusting means are formed on the surface of the substrate of the voltage controlled oscillator. 3. The method of claim 2, Wherein a conductor constituting the first variable capacitor and the second variable capacitor is formed on the substrate surface of the voltage controlled oscillator. The method of claim 3, Wherein a conductor constituting the first variable inductor and the second variable inductor is formed on the surface of the substrate of the voltage controlled oscillator. 5. The method of claim 4, Wherein a conductor constituting a variable capacitor and a variable inductor is formed on a surface of a substrate of the voltage controlled oscillator. 6. The method of claim 5, Wherein a conductor constituting a variable capacitor and a variable inductor is formed on a surface of a substrate of the voltage controlled oscillator. Performing functional trimming with respect to the conductor constituting the oscillation frequency adjusting means for adjusting the frequency of the oscillation signal to once roughly adjust the oscillation frequency; Adjusting the voltage control sensitivity to a specific value by performing a functional trimming on the conductor constituting the voltage control sensitivity adjusting means for adjusting the voltage control sensitivity, And performing a functional trimming again on the conductor constituting the oscillation frequency adjusting means to adjust the oscillation frequency to a specific value. Performing functional trimming on a conductor constituting the first variable capacitor to adjust the oscillation frequency roughly once, Performing functional trimming on a conductor constituting the second variable capacitor to adjust the voltage control sensitivity to a specific value; And adjusting the oscillation frequency to a specific value by performing functional trimming again on the conductor constituting the first variable capacitor. Performing a functional trimming on a conductor constituting the first variable inductor to once roughly adjust the oscillation frequency; Adjusting the voltage control sensitivity to a specific value by performing a functional trimming on a conductor constituting the second variable inductor, And adjusting the oscillation frequency to a specific value by carrying out functional trimming again on conductors constituting the first variable inductor. Performing functional trimming with respect to the conductor constituting the variable inductor to once roughly adjust the oscillation frequency; Adjusting the voltage control sensitivity to a specific value by performing a functional trimming on the conductor constituting the variable capacitor, And adjusting the oscillation frequency to a specific value by carrying out functional trimming again on conductors constituting the variable inductor. Performing a functional trimming on a conductor constituting the variable capacitor to roughly adjust the oscillation frequency once, Performing a functional trimming on a conductor constituting the variable inductor to adjust the voltage control sensitivity to a specific value; And adjusting the oscillation frequency to a specific value by performing functional trimming again on the conductor constituting the variable capacitor.